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Hambams CLS Chemistry Exam Questions
Rotation exam
185
Chemistry
Professional
11/08/2011

Additional Chemistry Flashcards

 


 

Cards

Term

An International unit (IU) of enzyme activity is the quantity of enzyme that:

 

 

 

Converts 1 μmol of substate to product per minute

 

Definition

 

 

Term

Which enzyme statement below describes a nonkinetic enzyme assay ?

 

 

Initial absorbance is measured, followed by a second reading after 5 minutes

Definition
Term

Which if the following statements regarding enzymatic reactions is true ?

 

 

The enzyme increases the rate  of the reaction

Definition
Term

Which statement about enzymes is true ?

 

 

 

A competetitive inhibitor will alter the apparent Km (Michaelis-Menten Constant) of the reaction

Definition
Term

Which substrate concentration is needed to achieve zero-order conditions ?

 

 

> than 99 x K m

 

Definition
Term

Which statement is true ?

 

 

Apoenzyme + prosthetic group = holoenzyme

 

 

 

Definition
Term

Which of the following statements about enzymatic reactions is true ?

 

 

 

NADH has absorbance maximum at 340 and 366 nm

Definition
Term

The increase in the level of serum enzyme used to detect cholestatic liver disease is caused mainly by :

 

 

 

Increased production and secretion by cells

Definition
Term

Which enzyme below is considered most tissue specfic ?

 

Alcohol dehydrogenase

(along with ALT-necrotic liver disease)

Definition
Term

Which of the following enzymes is activated by calcium ions?

 

Amylase

Definition
Term

Which of the following enzymes is a transferase ?

 

CK

 

(not - Alkp,Amy,LD)

Definition
Term

Which statement about the methods for measuring LD is true ?

 

The pyruvate to lactate reaction proceeds at about twice the rate as the forward reaction

Definition
Term

Which condition produces the highest elevation of serum lactate dehydrogenase ?

 

Pernicious Anemia

Definition
Term

Which condition is the LD most likely to be within normal limits .?

 

Acute appendicitis

 

(not hepatic ca,pulmonary infarct,crush injury)

Definition
Term

Following an acute MI, activity of LD usually peaks:

 

Three days postinfarction and returns to normal after 1 week.

Definition
Term

The LD pleural fluid:serum ratio for a transudative fluid is usually :

 

 

1:2 or less

Definition
Term

Which type of liver disease would you expect the greatest elevation of LD ?

 

Toxic hepatitis

 

(not etoh hepatitis,cirrhosis,acute viral hepatitis)

Definition
Term

Which of the following conditions will interfere with measurement of LD ?

 

 

Slight hemolyis during sample collection 

 

(LD is stable 2 days at RT or 1 week in refer)

Definition
Term

In the Oliver-Rosalki method, the reverse reaction is used to measure CK activity. The enzyme used in the coupling reactions are:

 

 

Hezokinase and G6PD

Definition
Term

In the Oloiver-Rosalki method for CK, adenosine monophosphate(AMP) is added to the substrate in order to :

 

 

Inhibit adenylate kinase

 

Definition
Term

Which substance is used in the CK assay to activate the enzyme ?

 

 

 

N-acetylcysteine

Definition
Term

Specimen for CK performed on an automated analyzer gives an error flag indicating substrate depletion. The sample is diluted x2 and x4. After correction the results are as follows:

x2=3000       x4=3600    Explanation ?

 

An endogenous competitive inhibitor is present in the serum

Definition
Term

2 hour old citrated coag sample, can we add on a CK?

 

No, citrate will interfere

Definition
Term

Which of the statements below regarding total CK is true?

 

Highest levels are seen in Duchenne's Muscular Dystrophy.

Definition
Term

Which of the following statements regarding the clinical use of CK-MB (CK-2) is true ?

 

Mass unit assays are more sensitive than electrophoretic methods

Definition
Term

Isoforms of CK are:

 

 

 

Formed in the circulation by hydrolysis of lysine from CK-MM and CK-MB

Definition
Term

A patient's CK-MB is reported at 18 and the total CK as 560. What is the CK relative index?

 

3.2%

 

CKI =    CK-MB     x 100

Total CK

Definition
Term

In a nonmyocardial as opposed toa myocardial cause of an increased serum or plasm CK-MB, which would be expected?

 

 

An increase in CK-MB that is persistent.

Definition
Term

Which statement best describes the clinical utility of plasma or serum myoglobin ?

 

Levels below 100 on admission and 2-4 hours postadmission help to exclude a diagnosis of acute MI.

Definition
Term

What is the typical time course for plasma myoglobin following an acute MI ?

 

Abnormal with in 3 hours, peaks within 12 hours, returns to normal in 36  hours.

Definition
Term

What is the typical time course for plasma TnI or TnT following an acute MI ?

 

Abnormal within 4 hours, peaks within 24 hours, returns to normal in 1 week

Definition
Term

Which of the following is the most effective serial sampling tiem for ruling out acute MI using both myoglobin and a cardiac spedific marker in an emergency department environment ?

 

Admission, 3 hrs, 6 hrs and a final sample within 12 hrs

Definition
Term

Whic of the cardiac markers is consistently increased in persons who exhibit unstable angina ?

 

Troponin T

Definition
Term

Patient has a myoclobin level of 10 at admission. three hours later the myoglobin is 14 and the Tropponin I is 0.04 (ref 0.0-0.4) Results are consistent with what condition ?

 

No evidence of myocardial or skeletal condition .

Definition
Term

A patient has a plasma CK-MB of 14 at admission and a totla CK of 170. Myoglobin is 130 and TnI is 1.6. Three hours later the cK-MB is 24. What best descrives this situation ?

 

This patient has had an acute MI and further testing is unnecessary.

Definition
Term

EDTA sample for TnI assay gives result of 0.7(ref0.0-0.4). The test is repeated three hours later and is 0.6, six hours later is 0.7. Most likely explanation ??

 

The patient has suffered cardiac injury, probably less severe than an MI.

Definition
Term

Which of the following lab tests is a marker for ischemic heard disease ?

 

Albumin cobalt binding.

Definition
Term

Which test provides the earliest warning of increased risk of coronary artery disease ?

 

High sensitivity CRP

Definition
Term

Which statement best describes the clinical utilitity of B-type natriuretic peptide (BNP) ?

 

A normal test result helps rule out congestive heart failure in persons with symptoms associated with coronary insufficiency.

Definition
Term

Which best describes the clinical utility of plasma homocysteine ?

 

High plasma levels are assiciated with atherosclerosis and increased risk of thrombosis.

 

Definition
Term

Which of the following statements about the aminotransferases  (ALT & AST) is true ?

 

Both transfer an amino group to α-ketoglutarate

Definition
Term

Select the products formed from the forward reaction of AST ?

 

 

 

Oxaloacetate and glutamate

Definition
Term

Select the products formed form the forward reaction of ALT ?

 

 

Pyruvate and glutamate

Definition
Term

Which of he statements below regarding the methods of Henry for AST and ALT is correct ?

 

Hemolysis causes positive interference in both AST and ALT assays

Definition
Term

Select the coupling enzyme used in the kinetic reaction of Henry ?

 

 

Malate dehydrogenase

Definition
Term

What is the purpose of LD in the kinetic method of Henry for AST ?

 

Rapidly exhausts endogenous pyruvate in the lag phase

Definition
Term

Which statement regarding the naming of transaminases is true ?

 

SGPT is the old abbreviation for ALT

Definition
Term

Which statement accurately describes serum transaminase levels in AMI ?

 

AST peaks 24-48 hours after an acute MI and returns to normal with 4-6 days

Definition
Term

Which condition gives rise to the highest serum level of transaminases ?

 

Acute hepatitis

Definition
Term

In which liver disease is the DeRitis ratio (ALT:AST) usually greater than 1.o ?

 

Acute hepatitis

 

(ALT prevails over AST in acute hepatitis, but AST is higher than ALT in chronic hepatitis, carcinoma and cirrhisis of the liver)

Definition
Term

Which of the following liver diseases produces the highest levels of transaminases ?

 

 

Chronic hepatitis

Definition
Term

Which of the following statements regarding transaminames is true ?

 

ALT is far more spedific for liver diseases than is AST

Definition
Term

Select the most sensitive marker for alcoholic lever disease ?

 


GGT

Definition
Term

Which enzyme is least useful in differentating necrotic from obstructive jaundice ?

 

 

LD

Definition
Term

Which of the statements below about the phosphatases is true ?

 

They are divided into two classes based upon pH needed for activity (alkaline or acid)

Definition
Term

Which of the following statements regarding ALP is true ?

 

 

Pregnant women have a higher lever of serum ALP than other adults

Definition
Term

Which isoenzyme of ALP are inhibited by L-phenylalanine ?

 

 

Intestional and placental

Definition
Term

Which isoenzyme of ALP is most heat-stable ?

 

 

Placental

 

 

Definition
Term

Which isoenzyme of ALP migrates farthers toward the anode (+) when electrophoresed at pH 8.6 ?

 

 

Liver

Definition
Term

Which isoenzyme of ALP is inhibited by urea ?

 

Bone

Definition
Term

Which of the following statements regarding ALP is true ?

 

 Elevated serum ALP seen with elevated GGT suggests a hepatic source

Definition
Term

In which condition would an elevated serum alkaline phosphatase be likely to occur ?

 

Squamous cell carcinoma

Definition
Term

Which condition is least likely to be associated with increased serum ALP concentrations ?

 

 

Osteoporosis

Definition
Term

Which substrate is used in the Bowers-McComb method for ALP ?

 

p-Nitrophenylphosphate

Definition
Term

Which of the following buffers is used in the IFCC recommended method for ALP ?

 

 

2-amino-2-methyl-1-propanol

Definition
Term

Serum form a 50 year old collected following digital exam. Prostatic acid phos 6.o (upper ref 3.0)

PSA 2.0 (upper ref 4.0) Most likely explanation ?

 

 

Acid phos is falsely elevated by prostatic irritation

Definition
Term

Which definition best describes the catalytic activity of amylase  ?

 

Hydrolyzes second a-1-4-glycosidic linkages of starch,glycogen and other polyglucans 

Definition
Term

Which of the following anylase methods is typically based upon a rate reaction ?

 

 

Turbidimetric

Definition
Term

How soon following acute abdominal pain due to pancreatitis is the serum anylase level expected to rise ?

 

 

 

2-12 hours

Definition
Term

Which of the statements below regarding the diagnosis of pancreatitis is correct ?

 

 

 

Diagnostic sensitivity is increased by assaying both amylase and lipase

Definition
Term

Which of the following conditions is associated with a high level of S-type anylase ?

 

Mumps

 

S-salivary

Definition
Term

Which of the statements regarding amylase methods is true ?

 

Amyloclastic methods measure the production of glucose.

Definition
Term

Which of the following statements regarding amylase methods is true ?

 

Synthetic substrates can be conjugated to p-nitrophenol (PNP) for a kinetic assay ?

 

Definition
Term

The reference method for lipase uses olive oil as the substrate because ?

 

Other esterases can hydrolyze triglyceride and synthetic diglycerides

Definition
Term

Which statement about the clinical utility of plasma or serum lipase is true ?

 

Lipase is not incresed in mumps, malignancy or ectopic pregnancy

Definition
Term

The reference method for serum lipase is based upon :

 

Titration of fatty acids with dilute NaOH following controlled incubation of serum with olive oil

Definition
Term

The most commonly employed method of assay for plasma or serum lipase is based upon:

 

Peroxidase coupling

 

Definition
Term

Which of the following enzymes is usually depressed in liver disease ?

 

 

Pseudocholinesterase

Definition
Term

A serum ALP lever greater than twice the elevation of GGT suggests:

 

 

Bone disease or malignancy

Definition
Term

How many of the substances below would be neede to enable an early diagnosis of stroke ?

 

D-Dimer, vonWillebrand's factor, matric metalloproteinase-9, S100B, BNP, vascular cell adhesion molecule .

 

 

All six

Definition
Term

Which of the following  hormones is often decreased by approx 25% in the serum of pregnamt women who have a fetus with Down's Syndrome ?

 

EStriol (E3)

Definition
Term

The syndrome of anapprioate antidieuretic hormone secretion (SIADH) causes:

 

 

Urine osmolality to be lower than that of plasma osmo

Definition
Term

Select the hormone that is associated with galactorehea, pituitary adenoma, and amehorrhea ?

 

 

Prolactin

Definition
Term

Zollinger-Ellison(Z-E) syndrome is characterized by great (20 fold) elevation of :

 

 

Gastrin

 

Definition
Term

Which statement about multiple endocrine neoplasia (MEN) is true ?

 

 

It is associated with hyperplasia or neoplasia of at least two endocrine organs

 

Definition
Term

Select the main estrogen produced by the ovaries and used to evaluate ovarian function ?

 

 

Estradiol (E2)

 

 

E2 is the major estrogen produced by the ovaries

Definition
Term

When pituitary adenoma is the cause of decreased estrogen production, an increase of which hormone os most frequently responsible ?

 

Prolactin

Definition
Term

Which of the following statements is correct in aaesing GH deficiency ?

 

 

Pituitary failure may involve one, several, or all adenohyphophyseal hormones, but GH deficiency is usually found.

Definition
Term

Which statement best describes the level of GH in patients with pituitary adenoma associated with acromegaly ?

 

 

Some patients require a glucose suppression test to establish a diagnosis

Definition
Term

Hyperparathyroidism is most consistently associated with ?

 

 

Hypophosphatemia

 

(Inc serum Ca , dec serum phos)

Definition
Term

Which statement reagarding the use of PTH is true ?

 

 

 

PTH levels differentiate primary and secondary cause of hypocalcemia

Definition
Term

The best method of analysis for serum PTH involves using antibodies that detect ?

 

 

 

Both the amino-terminal fragment and intact PTH

Definition
Term

Which of the following is most often elevated in hypocalcemia associated with malignancy ?

 

 

 

Parathyroid hormone related protein (PTHRP)

Definition
Term

Steroids with a dihydroxyacetone group at C17 are sclassified as :

 

 

17-hydroxycorticosteroids

 

Definition
Term

Which statement below regarding adrenal cortical dysfunction ?

 

 

 

Cushing's syndrome is associated with glucose intolerance

Definition
Term

Which of the following statements about cortisol in Cushing's syndrome is true ?

 

 

24 hour urinary free cortisol is a more sensitive test than plasma total cortisol

Definition
Term

Which of the following diseases is characterized by primary hyperaldosteronism caused by adrenal adenoma, carcinoma, or hypoplasia ?

 

 

Conn's disease

Definition
Term

Which of the following is the most common cause of Cushing's syndrome ?

 

 

 

Overuse of Corticosteroids

Definition
Term

Which of the following is the mechanism causing Cushing's disease ?

 

 

Excess secretion of pituitary ACTH

Definition
Term

In which situation is the plasma or 24-hour urinary cortisol not consisent with the clinical picture ?

 

 

Evaluation of congenital adrenal hyperplasia

 

 

Definition
Term

Which test is used to distinguish Cushing's disease (pituitary Cushing's) from Cushing's syndrome ?

 

 

Serum ACTH

 

 

Definition
Term

Whic is the most widely used screening test for Cushing's syndrome ?

 

 

Overnight dexamethasone suppression test

Definition
Term

Which test is the most specific for the establising a diagnosis of Cushing's disease (pituitary Cushing's) ?

 

 

Petrosal sinus sampling following corticotropin-releaseing hormone stimulation

Definition
Term

Which of the statements below regarding the catecholamines is true ?

 

 

Plasma levels show both diurnal and pulsed variation

Definition
Term

Which assay using 24 hour urine is considered the best single screening test for pheochromocytoma ?

 

 

Metanephrines

 

Definition
Term

Which metabolite is most often increased in carcinoid tumors of the intestines ?

 

 

5-hydroxyindolacetic acid (5-HIAA)

Definition
Term

Which statement regarding the measure ment of urinary catecholamines is true ?

 

 

24 hour urinary catecholamine assay avoids pulse variations associated with measurement of plasma catecholamines

Definition
Term

Which method used to measure catecholamines is the least specific ?

 

 

 

Measurement of fluorescence following oxidation by potassium ferrocyanide

Definition
Term

Which statement about sample collection for catecholamines and metabolites is true ?

 

 

24 hour urine creatinine should be measured with vanillymandelic acid, homovanillic acid, or metanephrines

Definition
Term

Which statement below applies to both measurement of VMA and metanephrines in the urine ?

 

 

Both can be measured by specific HPLC and GC-MS asays

Definition
Term

Thyroid hormones are derived from the amino acid ?

 

 

Tyrosine

 

Definition
Term

Which statement regarding thyroid hormones is true ?

 

 

T3 is about tenfold more active than T4

Definition
Term

Which of teh statements below regarding thyroid hormones is true ?

 

 

 

Total T3 and T4 are influenced by the level of thyroixine-binding globulin

Definition
Term

Which of the following conditions increase total T4 by increaseing thyroxine binding globulin (TBG) ?

 

 

Pregnancy or estrogens

Definition
Term

Select the most appropriate single screening test for thyroid disease ?

 

 

TSH assay

Definition
Term

The serum TSH level is decreased in :

 

 

Primary hyperthyroidism

Definition
Term

Which assay is the most specific and sensitive test for diagnosing thyroid disease ?

 

 

 

Thyrotropin releaseing hormone (TRH)

Definition
Term

Which of the following statements is true regarding reverse T3 (rT3)  ?

 

 

 

Formed in the blood by degradation of T4

Definition
Term

A patient has an elevated serum T3, and Free T4 and a very low serum TSH. What is the most likely cause of these results ?

 

 

Primary hyperthyroidism

Definition
Term

A serum thyroid panel reveals an increase in Total T4, normal TSH , and normal Free T4. What is the most likely cause of these results ?

 

 

Euthyroid with increased thyroxine-binding protein

Definition
Term

Which statement about TSH and T4 in early pregnancy is correct ?

 

 

TSH falls and thyroid hormone levels rise

Definition
Term

In which case might a very low plasma TSH result not correlate with thyroid status ?

 

 

After high dose corticosteroid treatment

Definition
Term

In which case below is qualitative analysis of the drug usually adequate ?

 

 

 

To determine whether the patient has been taking amphetamines

Definition
Term

The term pharmokinetics refers to the :

 

 

Relationship between drug dose and the drug blood level

Definition
Term

The term pharmacodynamics is an expression of the relationship between:

 

 

 

Drug concentration at target sites and physiological effect

Definition
Term

The study of pharmacogenomics involves which type of testing ?

 

 

Testing for single nucleotide polymorphisms known to affect drug metabolism

 

Definition
Term

Select the five pharmacological parameters that determine serum drug concentrations:

 

 

Liberation,absorbtion, distribution, metabolism, excretion

 

Definition
Term

Which route of administration is associated with 100% bioavailbility ?

 

 

Intravenous

Definition
Term

The phrase first- pass hepatic metabolism means that :

 

 

Some drug is matabolized from the portal circulation, reducing bioavailability

 

Definition
Term

Which formula can be used to estimate dosage needed to give a desired steady state blood level ?

 

 

Dose per hour = clearance (milligrams per hour) x average concentration at steady state / f

 

 

Definition
Term

Which statement is true regarding the Vd of a drug ?

 

 

Vd is the theoretical volume in liters into which the drug is distributes

Definition
Term

For drugs with first order elimination, which statement about drug clearance is true ?

 

 

Clearance = elimination rate/serum level

Definition
Term

Which statement about steady state drug levels is true ?

 

 

Oral dosing intervals result in peaks and troughs in the dose response curve

 

 

Definition
Term

If too small a peak trough difference is seen for a drug given orally then :

 

 

Dose interval should be increased

 

Definition
Term

If the peak level is appropiate but the trough level os too low at steady state, then the dose interval should:

 

 

 

Be shortened, but the dose per day not changed

Definition
Term

If the steady state drug level is too high, the best course of action is to:

 

 

Decrease the dose

Definition
Term

When should blood samples for trough drug levels be collected ?

 

 

 

Immediately before the next dose is given

 

Definition
Term

Blood sample collection time for peak drug levels :

 

 

Varies with the drug, depending on its rate of absorbtion

Definition
Term

Which could account for drug toxicity following a normally prescribed dose ?

 

Decreased renal clearance caused by kidney disease

Discontinuance of another drug

Altered serum protein binding caused by disease

All above:

 

 

Definition
Term

Select the elimination model that best describes most oral drugs ?

 

 

One compartment, linear first order elimination

 

Definition
Term

Drugs rapidly infused intravenously usually follow which elimination model ?

 

Biphasic or two compartment with serum level rapidly falling in the first phase

 

Definition
Term

Which fact must be considered when evaluating a patient who displays signs of drug toxicity ?

 

 

Drug natabolites (eg-N-acetylprocanimide) may need to be measured as well as the parent drug toxicity

Definition
Term

When a therapeutic drug is suspected of causing toxicityl, which specimen is the most appropriate for an initial investigation ?

 

Peak blood sample

Definition
Term

For a drug that follows first order pharmacokinetics, adjusting of dosage to ahcive the desired blood level can be made using which formula ?

 

New dose=     current    x conc at steady state

desired conc

Definition
Term

For whcih drug group are both peak and trough measurement usually required ?

 

 

Aminoglycoside antibiotics

Definition
Term

Which is the following statements about TLC for drug screening is true ?

 

 

 

A drug is identified by comparing the Rf value and staining to standards

Definition
Term

The EMIT for drugs of abuse uses an :

 

 

Enzyme conjugated to a drug

 

Definition
Term

Which statement about EMIT is true ?

 

 

 

Formation of NADH is monitored at 340 nm

Definition
Term

Which statement below regarding FPIA is true ?

 

 

Separation of free and bound labeled antigen is not required

 

Definition
Term

Quantitation of a drug by gas chromotography-mass spectroscopy (GC-MS) is usually performed in which mode ?

 

 

Selective ion monitoring

 

Definition
Term

A urine sample is received in the laboratory with the appropriate custody control form and a request for drug of abuse screening. Which test result would be a cause for rejection of the sample ?

 

 

Creatinine level of 5 mg/dl

 

Definition
Term

Which statement about the measurement of carboxyhemoglobin is true ?

 

 

 

Bichromatic analysis is required in order to eliminate interference by oxyhemoglobin

 

Definition
Term

Which is the following statements about blood alcohol measurement is correct ?

 

 

Symptoms of intoxication usually begin when the level exceeds 0.05 % w/v

Definition
Term

Which drug can be detected with ferric chloride in perchloric-nitric acids ?

 

 

Phenothiazines

 

Definition
Term

Which specimen is the sample of choice for lead screening ?

 

 

Whole blood

Definition
Term

Which of the following enzymes can be used to measure plasma or serum salicylates ?

 

 

Salicylate hydroxylase

Definition
Term

Which of the following tests is least essential to the operation of a ER ?

 

 

Lead

 

Definition
Term

Which of the following tumor markers is classified as a tumor suppressor gene ?

 

 

 

BRCA-1

 

Definition
Term

In general , in which of the following situations is the analysis of a tumor marker most useful ?

 

 

Testing for recurrence 

Definition
Term

Which of the following enzymes is increased in persons with prostate and small cell lung cancer ?

 

 

 

Creatine kinase-1 (CK-1 / CK-BB)

 

often present w/maligancies

Definition
Term

Which of the following is the best analyte to monitor the recurrence of ovarian cancer ?

 

 

CA-125

 

Definition
Term

Which tumor marker is associated ith cancer of the urinary bladder ?

 

 

 

Nuclear matrix protein

 

Definition
Term

A person presents with a Cushingoid appearance and an elevated 24-nr uring cortisol level. Plasma adrenocotropic hormone(ACTH) is very elevated and the clinicial suspects the cause is ectopic ACTH production. Which test would be most useful in substantiating this diagnosis ?

 

Alkaline phosphatase isoenzymes

Definition
Term

Which of the following statements regarding the Philadelphia chromosome is true ?

 

 

It results from a translocation of the long arm of chromosomes 9 and 22

Definition
Term

What is the primary clinical utility of measuring CEA ?

 

 

 

Monitoring for recurrence of cancer

 

Definition
Term

Which tumor marker is used to determine the ussefulness of trastuzumab(Herceptin) therapy for breast cancer ?

 

 

 

HER-2/neu

 

 

Definition
Term

A person is suspected of having testicular cancer. Which type of hCG test would be most useful ?

 

 

Plasma immunoassay for intact hCG and the β-hCG subunit

Definition
Term

A patinet is treated for a germ cell tumor has a total and free bhcg assay performed one week prior to surgery. The result is 40,000 and one week following surgery the result is 5000. Chemo is started and one week later the result is 10,000. What does this indicate ?

 

Transient hCG increased by chemotherapy.

 

 

Definition
Term

Which set of results for ER and PR is associated with the highest likelhood of a favorable response to treatment with estrogen suppression therapy (tamoxifen)?

 

 

ER positive, PR positive

 

 

(receptor assays performed on breast tissue bx to determine the potential response to tamoxifen)

 

 

Definition
Term

Which type of cancer is associated with the highest level of AFP ?

 

 

Hepatoma

Definition
Term

Which of the following assays is recommended as a screening test for colorectal cancer in persons over 50 years old ?

 

 

Occult blood

 

 

Definition
Term

Which of the following substances is used to determine the rick of developing cancer ?

 

 

 

p53 gene

Definition
Term

A person has an elevated 24 hour urinary homovanillylic acid (HVA) and vanillymandelic acid (VMA). Urinary metanephrines, chromogranin A, and neuron-specific enolase are also elevated but 5-hydroxyindoleacetic acid is within the reference range. What is the most likely diagnosis ?

 

Neuroblastoma

 

 

 

Definition
Term

In which of the following conditions is the PSA least likely to be increased ?

 

 

Post-digital rectal examination

Definition
Term

Which if the following statements regarding PSA is true ?

 

 

Free PSA below 25% is associated with malignant disease

 

 

Definition
Term

A 55 year old male with early stage prostate cancer diagnosed by biopsy had his prostate gland removed. His PSA prior ro surgery was 10.0 . If the surgery was successful in completely removing the tumor cells, what would the PSA result be 1 month after surgery ??

 

 

Undectectable

Definition
Term

Which of the procedures below can be used to evaluate a new glucose mehtod for proportional error ?

 

 

 

Add 5.0 mg of glucose to a 1.0 mL of a serum of knwon concentration and measure

(proportional error is percentage deviation from the expected result and affects the slope of the calibration curve. It causes a greater absolute error as concentration increases?

Definition
Term

Which of the two instruments can be assumed to have a narrower bandpass ?  Assume that wavelength is accurately calibrated.

 

The instrument giving the highest absorbance for a solution of 0.1 mmol/L NADH at 340 nm.

Definition
Term

A patient wha has a positive urinalysis for glucose and ketones has a glycoslylated Hgb of 4.0 % A fasting glucose performed the previous day was 180 mg/dL. Assuming QC was ok, what would you do ?

 

 

Request a new sample and repeat the glycosylated Hgb

Definition
Term

Laboratory results on a patient from the ED are :

Glucose = 1100 mg/dL

Na = 155 mmol/L

K = 1.2 mmol/L

Cl = 115 mmol/L

TCO2 = 3.0 mmol/L

Explanation for these results ?

 

Sample is drawn above the intravenous catheter

 

 

Definition
Term

A quantitative urine glucose level was determined to be 160 mg/dL by the Trinder glucose oxidase method. The sample was refrigerated overnight and the glucose the next day was 240 mg/dL with the polarographic method. What is the most likely cause of the discrepancy ?

 

 

High levels of reducing substances interfering with the Trinder reaction

 

Definition
Term

A tech is asked to use the serum from a clot tube left over from a chemistry profile run at 8 am for a stat ionized calcium. The tech should ?

 

 

Request a new sample

( ionized ca is pH dependant and heparin is preferred)

Definition
Term

A quantitative sandwich enzyme immunoassay for intact serum hCG was performed on week 4 and the result was 40,000 mIU/ml(ref 10,000-80,00) A clinician suspects a molar pregnancy and requested that the lab repeat the test checking for the hook effect. What process would identify this problem ?

 

 

Perform a serial dilution of the sample and repeat the test

Definition
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